To change the plane of focus from one object or character to another within a shot is commonly known as a rack focus.

The lens adapter gives the depth of field of a film camera, thus being able to do proper rack focus for story control.

A rack focus in filmmaking and television production is the practice of changing the focus of the lens during a shot.

Newer Sony consumer models offer Spot Focus mode as a means for rack focus.

Rush directed three films for AIP in the late 1960s exploring counter-cultures of the period and also introducing racking focus, a technique Rush claims to have discovered and named.

It was while rewatching some of his favorite science fiction films he realized Pixar's films lacked the look of 70 mm film and its barrel distortion, lens flare and racking focus.

Lens breathing does not prevent one from racking focus or following focus with this lens, but it lessens the desirability of any type of focus adjustment, since it noticeably changes the composition of the shot.

It is usually operated by a focus puller (often called the 1st assistant camera, or 1st AC) but some camera operators prefer to pull their own focus (the act of changing focus is called "pulling" or racking focus).

The sharply unpredictable editing, the hypnotic use of slow motion and rack focus (that's when the background and foreground reverse in clarity), the ominous rock music - everything adds up to a debut of singular confidence, full of fun and creepiness."